The Mechanism Analysis of Anti clogging Arching Structure in Dredged Sludge

A number of lands were occupied by discarding the dredged sludge in the yard as waste materials.The Aeration Vacuum rapid Mud Water Separating (AVMWS) technique was appropriate for discarding yard with high water content and high clay particle content sludge.This technique could quickly reduce the volume of the sludge and accelerate the turnover use of the yard.In addition,the technique could overcome the clogging problem when pumping water from high water content, high clay particle content dredged sludge.Through the sampling particle size distribution tests after AVMWS and conventional vacuum pumping model tests, it was found that in the AVMWS tests the fine grained soil run off, coarse particles accumulated, and arching structure layer was formed.However, in the conventional vacuum pumping tests, fine particles did not lost and there was clogging without arching structure layer.The layer could protect the internal loss of the fine particles and ensure a high permeability of the soil at the same time.And the mechanism was explained as well.